Effects of the high-fat and high-cholesterol diet and metformin supplementation on testicular intrinsic apoptosis pathway regulators, including (a) the ratio of Bax:Bcl-xl, cytochrome c (Cyt c), cleaved-caspase 9 (C-Cas9), caspase 3 (Cas3), cleaved-caspase 3 (C-Cas3), poly (ADP-ribose) polymerase (PARP) and cleaved-PARP (C-PARP) and (b) caspase 8 (Cas8), caspase 3 (Cas3), cleaved-caspase 3 (C-Cas3), PARP and cleaved-PARP (C-PARP) in the male mice: Protein expressions in each group were measured using western blot analysis, and β-actin was used for normalization. Data are expressed as means ± SD of duplicate experiments (n = 6–9 per group). * p < 0.05 as determined by one-way ANOVA followed by LSD post hoc test. NC, normal diet; HFC, high-fat and high-cholesterol diet; HFC + Met, HFC with metformin supplementation.